How to Keep Your Air Conditioner From Freezing Up

Ironically enough, even on a sweltering summer day, you can find your AC unit coil or refrigerant lines encased in ice! So how can you keep your coil from freezing?

The first thing you can do is make sure you don’t have a dirty air filter. Good airflow is vital to keep your air conditioner from freezing. Changing your filter at least 4 times a year (if not monthly) will also help your indoor air quality and improve the performance of your heating and cooling system, saving you money in the long run as dirt in the filter can be preventing air from flowing freely through the system. 

Another step you can take to ensure your HVAC system doesn’t freeze over is to have your professional HVAC service technician check for low refrigerant levels and refrigerant leaks. When your AC unit is low on refrigerant it works much harder, and the drop in pressure within the unit can cause the evaporator coil to freeze over. 

Alternatively, your condensate drain line can be causing an issue and contributing to your air conditioner’s freezing. As your air conditioner cools warm air it absorbs the heat out of the air and transfers it outdoors. As this happens, water vapor moisture is condensed out of the air and is delivered through the condensate drain line. If the line becomes clogged with debris the water can back up, causing a leak. Additionally, the remaining humid air in the environment can make the evaporator coil more likely to freezing over. So in order to keep your AC freezing risk low, make sure that the drain line is clear!

Next, you need to check those vents! Make sure that both your supply registers and the return vents are clear and that no furniture is blocking them. Make sure no more than 2 or 3 vents are closed at any given time. Restricting too much airflow in your AC system can also cause your system to freeze up. 

Finally, make sure the blower fan on your HVAC system is working properly. Remember, airflow is key to keeping your AC unit from freezing, so a damaged or underperforming blower fan may be a sign that it’s time to call an AC repair tech.